Signal for automobiles



IVER.

.1. S-IOCKUIVI AND I. H. VAN SC SIGNAL FOR AUTOMOBILES.

APPLICATION FILED MARA I9, [920.

Patented Jan. SII 9 1922,

H. 1. STOCKUM AND1. H. VANSCIVEH.

SIGNAL FOR AUTOMOBILES.

APPLICAHQN F|LEDMAR.|9.1920.

Patented an. 3

3 SHEETS-SHEET. 2.

@v 'if /M my Wfl-MM TTORNEYS Hf). STOGKUM AND J. H. VAN SCIVER.

. SIGNAL FOR AUTOMOBILES.

APPLICATION FILED III/III. I9. I92o.v

Patented Jan. 3l, 1922.

stares HARRY J. STOOKUM, OF DELAWARE TOWNSHIP, CAMDEN COUNTY, NEWJERSEY,

Y AN JOSIAH HOWARD VAN SCIVER, OF lHILADELPI-IIA, PENNSYLVANIA, 1@LS-1SIGNORS TO AUTOIVLOBILE APPLIANCES CO., 0F PHILADELPHIA, PENNSYL. VANIA,A CORPORATION OF PENNSYLVANIA.

SIGNAL non AUTOMOBILES..

To all w/iom it may concern.'

Be it known that we, HARRY J. S'roon 'ai and' J. Howann VAN Soivnigbothcitizens 'of the United States, and respectively residents ofV Delawarel`ownsl'iip,

of Philadelphia, county of Philadelphia, State of Pennsylvania, haveinvented certain new and useful Improvements inv a Signal forAutomobiles, 'of which the following is a specification;

In the operation of automobiles,particui larly where traffic iscongested, it is neces 'and extending his arm outwardly from thevehicle. This kind of a signal is, however,

not lalways seen, or even capable of being seen, and where the vehicle.is closed, cannot even be made. Frequent and many signals of thiskind,also, are wearisome. 4Such a v signal, furthermore, is net readilyobserved at night,.particularly when the illumination is poor.

For the above reasons, therefore, numerous plans have been proposed forshowing a signal, for instance atl the rear of the ve- 'hicle lSonie ofthese plans provide for an illuminated signal' at night, and otherscontemplate: a signal manually operated from thedrivers seat by means ofwiies, cables, or links extending to the rear of the vehicle, whilestill other plans contemplate the operation of Asignals by electricitythrough the operation of a suitable switch,

also at thel drivers seat. The object of our invention about to bedescribed is to provide a signal mounted preferably upon the rear of avehicle and adapted-to be' displayed positively, plainly, andautomatically wheneveitlie vehicle is slowed or stopped,

whether in the day time or at night, and' without conscious attention onthe. part of the driven A further object of our invention is to providea'signal ofv the'character speciied which may be combined with the usualtail Specification of Letters Patent.

Camden County, State of New Jersey, and the city light in such a way asto have certain elements in common, thereby lessening the total numberof parts required and-'the corresponding cost of construction. A stillfun therl object of oui' invention is to provide a signal ofthecharacter specified which can be readily and simply attached to anautomobile of usual construction with'practica-illy no alteration ormutilation of parts. Yet another object of our invention is to provide aspecial valve movrnient forthe operat-ion of our improved signal wherebycertain disadvantages likelyto be niet .with in valves of usualconstruction will be eliminated.

' Ourinvention will be fully described hereinafter and the features ofnovelty will be'pointed out in the appended claims. Our invention willbe better understood by referring to the accompanying drawing in whichFig. 1 illustrates our invention in one form applied to a touring car ofusual construction, non-essential parts of the car' being shown dotted;Fig. 2 is an enlarged view, taken from the rear, of the speciiicembodiment of signal used in Fig. 1, the signal'being in olf position;Fig. 3 isa view, vsimilar to Fig. 2, the signal being in on position;Fig. Ll'is a side elevation of- F ig. 2, looking from the right; Fig. 5is an enlargcdldetail view, partly in section illustrating thecontrolling valve of Fig. 1,

and its connections; Fig. 6 is a detail section' of said valve in adiHerent position gY Fig.`

"ing our invention in a different forni; Fig.

ll is a re'ar view of Fig. 9, partly. in section;

Fig. 12 is a side elevation of F ig. (J looking from the right; Fig. 13is a sectional view showing the valve of Fig. 7i; adapted for" theformof our invention' illustrated in '4 Figs. 9 to 12 inclusive; Fig. 14 isa sectional view ofthe valve of Fig. 5 adapted for this latter forni ofour vinvention and Fig. 15 is a sectional view illustrating the valve'ofFig. 14 in a different position Patented Jan. 31, 1922.. applicationflied March 19, 1920. semi no. semis.' i I As shown in Figs. 1 to 4inclusive the signal lamp comprises a casing lof any suitableconstruction and shape and arranged to be mount-ed upon a convenientpart of the automobile, preferably at the rear, for instance, by meansof brackets 2 and 3. The casing 1 is provided with a glass front 4 uponwhich the word Stop is produced in any convenient manner so as tocontrast with the front Iitself. An obscuring disk 5' of suitable formand dimensionsto obscure the glass front 4, is rigidly mounted,exteriorly of the casing 1, upon a shaft 6, which is journalled insuitable bearings 7 and eX- tends into said casing 1 as shown in Fig. 4.This obscuring disk 5 may be termed a movable' indicator element andnormally rests in the position shown in Figs. 2 and 4, so as to coverthe face of the lamp. The disk 5 may be provided with a bulls eye 8 ofred glass if the front 4 is of white glass or if the latter is of redglass the bullseye may be omitted entirelyl from the opening in theobscuring disk. In the interior of the casing 1 the shaft 6 carries agrooved pulley 9 about which a flexible cable 10 extends, one end ofsaid cable being fastened to a coil spring 11 which is attached to afixed stud 12 and the other end of said cable being secured to a'piston13 mounted to reciprocate .in a cylinder 14. The latter is locatedwithin the casing 1 and is in communication with a tube 15 whichterminates exteriorly of said casing 1 inthe form of a suitable couplingor nipple 1G. Thecylinder 14 is provided further with an air vent 17 asshown in dotted lines in Figs. 2 and 3.

:A pipe 18 is connected at one end with the nipple 16 and at its otherend with the intake manifold 19 between the carburetor 20 and the engine21. At a suitable point, the pipe 18 is provided with a controllingvalve whereby the actuation of the signal coincidentally with thevoperation of the brake-pedal or equivalent element is brought about. Inorder to insure a maximum of eiiicieney it is desirable that the'controlling valveshould possess the following characteristics: first avery slight depression of the brake pedal or a slight actuation of itsequivalent, should open the valve fully; second, the valve once open,any further depression of the brake pedal or actuation of its equivalentshould have absolutely no effect upon the valve opening; nor should itexert any mechanical strain upon the valve or upon the pipe in which thevalve is located; third, the valve should always close easily andwithout hammeringand should not tend to overthrow on closure so as tostrain or jam the valve parts; fourth, the natural twisting, shaking andvibration of the parts necessarily' consequent' upon the operation ofthe vehicle should neither affeet the open or closed position of thevalve aaoacoa while the valve 22 is provided with a crankarm 26pivotally connected with a rigid stem 27 which is suitably connectedwith tne brake-rod 28 or equivalent element, the brake-rod beingconnected in theusual manner with the brake lever 29 and the Customaryfoot pedal 30. ln the arrangement illustrated in Fig. 5 the stem 27passes through an apertured head 31 which is located between a fixedcbllar 32 and a washer 33 on the stem 27, the latter at its free endbeing screw threaded for the accommodation of one or more nuts 34. Acoil spring 35 is located upon said stem 27 between the washer and nuts34 against both of which it bears. The apertured head 31 comprises vanintegral part of a member 3G which in turn is carried by a clampingmember 37.* The latter, in combination with a co-operating clampingvmember 38, constitutes a clamp which is secured upon the brake rod 28 orits `equivalent by means of clamp screws 39 as shown in Fig. 5. l

Suitable stops 40 and 41, preferably adjustable, may be provided on thevalve casing of the valve 22 to limit the movements of the crank-arm 2Gin opposite directions for the purpose to be more fully describedhereinafter. ln the normal condition of the parts, that is in theillustrated example, with the brake released the valve 22 occupies theposition shown in Fig. 5 in which the diametrical passage 23'registerswith the pipe 18 so that the connection between the cylinder 14 and theintake manifold 419 is uninterrupted. Assuming now that the engine 21 isin operation, the suction produced in the intake manifold 19 will beeffective,` through the 110 pipe '18 and valve 22. in the cylinder 14and upon the piston 13 therein, and as aresult will draw the latter tothe position shown in Fig. 2 and thereby exert a pull upon the cable 10against the tension of the v115 spring 11. By reason of the fact thatthe cable 10 passes about the-pulley9'the pull upon said cable willbring about a rotation of said pulley whereby the obscuring disk 5 ismoved toits lower position in which it 120 covers the lamp front 4, itbeing understood that at night the bulls eye 8 will show red in thecustomary manner with said disk in the position referred to. In otherwords, as long as the engine is running and the 125 valve 22 is in theposition shown in Fig. 5,`^

,the suction produced in the intake manifold, by acting upon the piston13, will main-'- i tain the obscuring disk 5 ina posi-tion in whlch theslgnal stop is covered, the

molines -spring 11 being stretchedv orunder tension trated example hewill depress the footbrake pedal 3 0 to operate the foot brake. Thiscauses the brake-rod 28 to move fore wardly in the direction of thearrow in Fig.

\ 5 'and by reason of its connection with the stem 21 causes a similarmovement of the latter in the same direction whereby the crank-arm A26is swung from they position shown in Fig. 5 tothe position shown in F G.The swinging vmovement of the crank-arm 26 .in this direction isarrested by the 4stop 41 and brings about a partial rotation ofthe valve22 in its casingsuflicient to move the passage 23 out of registry withthe pipe 18 and into registry with the relief aperture 25, the passage24 being coincidentally moved.' into registry with that section of thepipe 18 which extendsv between the valve 22 and cylinder 14. ln otherwords the valve 22 is adjusted to the position shown in Figz in whichcommuni-- cation between the cylinder 14 and the viiitake manifold-19 iscut off and the suction previously effective in said cylinder 14` isrelieved byA way of the. tube 15, pipe'lS, valve passages 24 and 23andrelief aperture 25. The piston 13 being thus relieved `from therestraining effect of said suction and resistance to the action of thespring 11 consequently being no longer present, the latter,

by contracting, will exert a pull, in the re-`4 veise direction upon thecable .10 which is communicated to the pulley 9 and thereby swings theobscuring disk 5 from the position shown in Fig. 2 to the positionillusw trated in F 3. ln this latter position of the disk 5 the wordStop is fully exposed and being plainly and contrastingly produced upon-the lamp front is readily visible :in the day time, the very movementof the obscuring disk serving to draw attention to the signal. At nightthelamp in the casing 1 being lighted, the'signal Stop7 will'necessarily stand out very plainly.

vIt will be understood that a continued vmovement of the. brake-rod 28in the direction of the arrow in Fig. 5 after the movement ofthe valve22 to the position shown in Fig. G will simply cause a compression ofthe spring 35so that'the valve and its connected' parts will-mot besubjected to any undue strain.' l

As pressure upon the brake-pedal 30er actuation of its equivalentceases, the valve 22 will be 4returned to itsj normal position shown inFig. 5, the movement in this ldirectionbeing arrested by the engagementof the crank-arm 26`v with the stop, 40; The

the pulley 9 in a direction to y,return the obscuriiig disk 5 to itslower -position in' which itl again covers the front of the lamp and thesignal Stopy During the reciprocating movements of the piston 13 air isdrawn into and expelledy from the cylinder v14- through the air vent 17.thus preventing the formation vof a vacuum or an air cushion behind saidpiston whereby its movements would be interfered with.

ln order to still further increase theV efficiency of operation we havedevised the special form of valve shown in Fig. 7 as a substitute forthel valve 22 and w ich in chicles all of the advantageous elaracteristics` hereinbefore set forth. As illustrated in Fig. 7 theconstruction comprises a casing 42 closed at one end by a preferablyremovable head '43 having a passage 44 which 4communicates with thatsection of the pipe '18'leading to the intake manifold 19; The

casing itself is provided with a. transverse passage 45 whichcommunicates with that section of the pipe 18 leading to the cylinder14, the two passages 44 and 45 being in com# munication' with eachlother through the casing 42 when the controlling valve is open. At itsopposite end the casing is formed with j an outwardly projecting boss 46having an .axial passage in which the valve stem 22at is slidable, saidstein being provided with flattened portions 22b or being otherwiseconstructed toprovide one or more air passages 47 as shown in Fig. 8.At'its inner endtlie axial-passage is constructed with a seat 48 the rod22e and b'ears with one end against the head 43 and with itsother .endagainst the neck 22d, the force exerted by said spring tending tomaintain vthe valve 22c upon its seat 48 and to returnit thereto.

The illustrated means for operating the valve comprises'a. .lever 26apivoted at one' end Vupon a lug 5 0 projecting from the boss 4G, saidlever extending through an open ing 51 in the v alve stein 22a'and'havin-g its other end connected with a stem 27a. In

the arrangement illustrated in- 7 the stem passes through a slidablesleeve'311 11o" for the accommodation of the valve'22cf" and at its freeend is provided with a fixed collar 34 which may be screw-threaded uponsaid stem for adjustment purposes. A coil spring 3:3 is located Anonsaid stem 27 between the sleeve 31'a.id lie collar 34 against both o t'which it bears.l rlhe sleeve 3l is embraced by and pivotally connectedwith a fork 36 carried by a spindle 36 rotatable in a bearing 37 formingpart ot' a clamping member 37 b. The latter in combination with acio-operating clamping member 38, constitutes a clamp which is securedupon the brake-rod 28 or its equivalent by means of clamp screws 39 anda set screw 39b as shown in Fig. 7. lt will be understood that thespring 35 is stronger than the spring 49,.the purpose of which willappear more fully hereinafter.

The ,rotatable spindle 36h, the pivota-lly connected sleeve 31, and thepivot whereby f the stem 27 is pivotally attached to the lever 26,together, serve as a universal `joint whereby the brake rod 28 or itsequivalent is connected with the valve. Asa result ot 4this arrangement,the brake rod 28 may be moved forward and backward by the brake pedaland lmay also move up and down and to one side or the other withoutbending or tending t0 bend or break any ot' the parts.

Normally the elements constituting the valve occupy the positions shownin Fig. 7 in which communication betweenthe fpassages 44 and 45 andconsequently between the pipe sections 18 is uninterrupted so that thesuction which is produced in the intake manifold is effective upon thepiston 13 which is thereby drawn to the position illustrated in Fig. 2in which the obscuring disk is in its lower position in front of thesignal. When the brake pedal 30 is depressed or an equivalent element isoperated to slow down the vehicle or bring it to a stop, the brake rod28 or its equivalent will be actuated in a direction to exert a pull onthe stem 27 whereby the lever 2G will be 'pivotally swung to the rightin Fig. 7. This brings aboutan axial movement of the stem 22 and movesthe Avalve 22c away Jfrom the seat 48 and the needle valve 22f into theend of the passage 44, the spring 49 being 'compressed by theseoperations. As soon as the needle valve 22f reaches the end ot thepassage 44 any continued actuation ot the brake pedal or its equivalentwill simply compress the spring 35 and thus have no straining effectupon the valve parts; as previously stated the spring35fL is strongerthan the spring 49 so that the initial pull on the stem 27 will bringabout a compression of said spring 49 by a shiftingl of the valve partswithout materially compressing the spring 35. y

As soon as the valve 22 is moved from its seat 48. and the valve 22fcloses the rec/tees passage 44, the effect of the suction pro- 3&5V

duced in the intake manifold upon the piston will be removed so that thelatter will be pulled back by the spring 11 and the obscuring` disk 5will be swung to the position shown in Fig. 3 in which the signal Stop,is exposed. Any vacuum which may remain iu that section ol the pipe 18which extends between the casing 42 and the cylinder 14 and in thelatter, after the valves 2Lc and 22i have been operated described, willbe quickly relieved by the air which flows through the passages 47 alongthe stem 221. As soon as the brake pedal or its equivalent is releasedthe parts will be returned to the position illustrated in Fig. 7 inwhich communication between the cylinder 14 andV the intake manifold isagain established. As a result the suction produced in the latter willagain become effective in said cylinder 14and upon the piston 13 thereinand will thus bring about a return movement of the obscuring disk 5 toits lower position in which-it again covers the signal.

In the form shown in Figs. 9 to 12 inclusive, the signal lamp l may be'of any usual construction, although, preferably, it should be ot'somewhat more than usual diameter.

Alt is mounted upon a bracket, 2 provided `minating said license plate.

The bracket 2 is shaped so as to provide a cylinder 14:2 in which ishoused a. slidable pistonA 13, of usual cup ring construction having apiston rod 13b pivotally connected with the slotted end ot' a crank arm10 which is itself pivotally attached by a shaft (3, to an arm whichprojects laterally from the bracket.

In this form also the glass `front. 4 of the lamp may be ot red glass,as usual, or of white glass, and has the word Stop paint ed or otherwiseformed thereupon i'n a color contrasting with that ot the front itself.

An obscuring disk 5 'is provided with an arm. the outer end offwhich islixedly attac-hed to the shaft 6, upon which is fixed the arm 10. This.obscuring disk ordi narily rests in the position shown in Figs. 3,

1.1 and 12 so as to cover-the tace ot the lamp.

manifold 19, between the carburetor 2() andl the engine 21 as in theform first described. Pipe 18 is provided with a valve, 22g

aient in the manner which mayl be of, usual constructionpor which may beoftheftwo-way type asshown in Figs. .14 and 15,'said valve`22g having acrank arm '26D pivotally `connected j by arigid stem 27" to a memberwhich may be is normallyineffectivevin the cylinder 14a because thevalve 22g occupies the position shown in F ig.- 1 4 in which'thevdiametrical passageQBais out lof registry with the pipe 18a: andcommunication between the cylinderV .14 and the intake manifold 19 isthus cut off. The obscuring disk 5a,.by,its own weight, thus lies in itslower position and `covers the signal, the bulls eye 8 showingv red atnight in the usual way.

' The' operation of the form-of our invention now being described is asfollows:

lWhen it is desired to slow or stop the car,

the driver,`as before, will,A besides cutting down his power, naturally.depress the foot bralke 30. This willy cause the valve l22g to' berotated through the movement of brake, rod 28 and bringsl thediametrical passage 23a into registry with the pipe 18al as shown inFig. "15,7thus opening cylinder 1.4i?, through pipe 18L to the suctionproduced in. the intake manifold. Piston 13a will therefore be forcedinwardly, thus raising the obscuring disk and -exposing the word Stopupon the lamp front. During the day this word Stop beingplainly andcontrastinglyprinted, will readily be seen,

'while atnight the lamp be'ing lighted, 'the word will necessarily standout veryplainly.

being described.

shown in Fi Vstruction as that shown in Fig.

vl/Vhen the foot bra-ke 30 or its equivalent is released the valve 22gwill be returned to the position shown in Fig. 14 in which communicationbetween the intake manifold and the cylinder 14a is again cut olf. VTheie-` sult of this is vthat the obscuring disk 5.afwill drop back infront of the signal by gravity, any vacuum which remains in the pipe 18abetween the valve casing and the ,cylinder 14a being `relieved by theair which Hows through the relief aperture 25a, passage 23, transversepassage 24a and pipe 18a.

in cases where the two-way valve of Figs.` 14 and 15 is not desired andthe type of valve is preferred, the valve arrangement illustrated inFig. 13 may be substituted in the form of our invention now eneral connand differs therefrom only in operation. In the present instance theneedle valve 22h by the action This valve is ofthe same Aof thespringlQzis maintained normally against the end vof the passage 44a toclose ,the same,.while the valve 22* is away from and permitting. the`obsouring disk 5 to' ifs ASeat 48a. vThe man is am @Dammiifv andconsequently betweenthe'in'take n'i'an'if-4v` fold lland'vthe'cylinder14;al is normally out...I 1

from the passage 44? against .theftensio'n of the spring 49?* and vatthe same-time willvseat'vl 'the valve 2.2i upon its seat 48a.' 'A vfreepractically'unrestricted passage is immedi-f.,

ately provided between theintake manifold v Y* 8O and the cylinder 14whereby the suction by lacting upon the piston 13a swings the obscuringdisk 5ZL to its raised position and .thus

exposes 4the signal Stop. As soon as the brakepedal orits equivalent isreleased the needle valve 22h will ibevmoved back to again close thepassage 44a and the valve 22v will4 be moved away Afrom iits seat L18"thereby C cutting olf the suction from the cylinder 14a return to itslower position by gravity and to aga-in' cover the signal; whatevervacuum f may remain between 'the piston and the valve is instantlyrelieved by the air which enters the channels 47a along the stem 221 inthe same wayas in the vform shown in Fig. 7.

-It will be understood that the spring 35h.

being stronger than the `spring 49a the initial pull on the cables276,7271 will have substantially no effect` thereon; said spring 35h.serving as a take-up in the same way as do'- thesprings and' of Figs. 5,and 7 respectively. y f ,l

vWe have shown the invention'as applied to a Stop signal only., thisbeing suiicient to illustrate the novel `principle"which-,we haveutilized, namely, the control .of the signal by means of the suctionproduced in thel intake manifold. Itv will be clear, however, totlioseskilled in the-art, that the same principle may be applied to theoperation of a right and left signal, and, furthermore, thattheprinciple may be so utilized as to l provide forboth a stop signaland right and left signals inthe same device, 'any one of such signalslosingl iiiade according to the need at the time.

vvVarious changes in the specific forms shown and described may be madewithin.- the scope of the claims without departing 120 from the spiritof our invention.

@E5 ycationjbetween the two sections-of pipe 18? 2. ln an automobile, asignal comprising a cylinder, a piston movable therein, an indicatorelement operatively connected withl the piston, Va pipe connecting thecylinder with the intake manifold, a valve for opening and closing thepassage in said pipe and a link connecting said valve with the brakelever, whereby said valve is operated concurrently with the brake andinf-accordance with the position thereof.

J3. in an automobile, a signal comprising an indicator element movablymounted upon the car, a cylinder also mounted upon the car, a pistonmovable in the cylinder and operatively connected with the indicatorelement, a pipe connecting the cylinder with the intake manifold, avalve in said pipe and a link connecting said valve with the brake pedalwhereby actuation of the brake operates the valve and, hence, causes thepiston to move so as to operate the indicator element coincidentally andin accordance with the brake.

4;. ln combination, in an automobile signal, a pipe extending from asuction source to an indicator element with which it is operativelyconnected, a valve in said pipe, and a universal joint connecting saidvalve with the brake pedal rod whereby said valve is operated in harmonyand coincidentally with the. brake. i

5. ln combination in an automobile signal, a pipe extending from asuction source to an indicator element with which'it is opera-a tivelyconnected,v a needle valve in said pipe,

and a universal joint connecting said valve with the brake pedal rodwhereby said valve is operated in harmony and coincidentally with thebrake.

6. ln'combination in an automobilesignal,

7, ln combination in an automobile signal, i a pipe extending from asuction'source to an indicator element with which it is operativelyconnected, a needle valve in said pipe, a spring for keeping said valvein its normal position, a connection slidably attached to the needleAvalve and secured to the ybrake pedal rod, and a compression springconnected with the needle valve and adapted to be engaged by saidlslidable connection when the brake pedal is depressed, the compressionspring being stronger than the first mentioned spring. y

8. ln combination in an automobile signal, a pipe extending'lfrom asuction source to an indicator element with which it is operatively.connected, a needle valve in Asaid pipe, a spring for maintaining saidvalve in its normal position, a slidable collar upon the needle valveconnected with the brake pedal, and a compression spring connected withthe needle valve, said sp-ring being stronger than the first mentionedspring and its inner end being disconnected from but adapted to beengaged by a slidable collar when the brake pedal is depressed. j,

9. The combination with a vehicle, of a motor for propelling the same, amovable indicator element mounted on the vehicle, a suction responsivedevice operated by the suctionv of the motor to maintain said indicatorelement in one position, means whereby said indicator element is movedto another position, and means controlled by the'driver whereby thesuction connection is opened and closed to cause said suction responsivedevice to actuv,withl said suction responsive device whereby saidelement is moved to a position to un cover said signal' and meanscontrolled by the driver whereby said suction responsive device and saidspring are selectively caused to actuate said indicator element.

l1. The combination of a signal, an indicator element arranged to coverand uncover said signal, a connection therefrom to a source' ot suction,a valve in said connection normally providing tree communication betweensaid source oi suction and said element whereby the latter is maintainedin its normal position to cover said Signal by suction and meanscontrolled by the driver for actuating said valve to cut offthe suctionfrom said element whereby the latter is moved from its normal positionto a position in which said signal is uncovered.

12. The combination of a signal, an indi -cator element arranged tocover and uncover said signal, a shaft carrying said indicator element,a cylinder, a piston movable therein and operatively connected with saidshaft to rock the same in'one direction, a connection from said cylinderto a source of suction, a valve in said connection normally providingtree communication between said sourceroi` opposite direction 00 movesaid indicator element to uncover said-signal when said suc'- 10 tion isout o'.

In testimony whereof We have hereunto set our hands.

HARRY J. sTooKuM. JosIAH HOWARD VAN soIvER.

